Cable connection structure and manufacturing method of the cable connection structure

Abstract

A cable connection structure includes a round cable, a flat cable, a holder holding an end portion of the round cable and an end portion of the flat cable and pulling out the round cable and the flat cable to overlap each other in a same direction, a connecting portion in which a core wire exposed from the end portion of the round cable and a conductor exposed from the end portion of the flat cable held by the holder are connected to each other, and a mold resin portion collectively covering the outer circumference of the holder and the outer circumference of the round cable and the flat cable pulled out from the holder.

What is claimed is: 
     
       1. A cable connection structure, comprising:
 a round cable having a round cross section and including a core wire and a round insulating sheath covering an outer circumference of the core wire; 
 a flat cable having a cross section in a flat rectangular shape and including a tabular conductor and a flat insulating sheath covering the conductor; 
 a holder holding an end portion of the round cable and an end portion of the flat cable and pulling out the round cable and the flat cable in a same direction in an overlapped state; 
 a connecting portion in which the core wire exposed from the end portion of the round cable and the conductor exposed from the end portion of the flat cable held by the holder are connected to each other; and 
 a waterproof exterior portion collectively covering, with an insulating resin, an outer circumference of the holder and an outer circumference of the round cable and the flat cable pulled out from the holder. 
 
     
     
       2. The cable connection structure according to  claim 1 , wherein
 the flat cable is bent to be guided in a direction different from a direction in which the flat cable is pulled out from the holder, and 
 the round cable and the flat cable are pulled out from the waterproof exterior portion in different directions. 
 
     
     
       3. The cable connection structure according to  claim 1 , wherein
 the waterproof exterior portion is a mold resin portion. 
 
     
     
       4. The cable connection structure according to  claim 1 , wherein
 the waterproof exterior portion is a heat shrinkable tube to which a thermoplastic adhesive is attached, and 
 the thermoplastic adhesive is in a solidified state, and the heat shrinkable tube in a shrunk state covers an outer circumference of the thermoplastic adhesive. 
 
     
     
       5. The cable connection structure according to  claim 1 , wherein
 the holder includes a round cable holder that holds the end portion of the round cable and a flat cable holder that holds the end portion of the flat cable, and 
 the round cable holder and the flat cable holder are capable of being joined together in such a manner that the round cable from the round cable holder and the flat cable from the flat cable holder are pulled out in the same direction in the overlapped state. 
 
     
     
       6. A manufacturing method of a cable connection structure, comprising:
 a cable setting step of holding, in a state in which a round cable and a flat cable are pulled out in a same direction in an overlapped state, an end portion of the round cable and an end portion of the flat cable in a holder; 
 a connecting step of connecting a core wire exposed from the end portion of the round cable held by the holder and a conductor exposed from the end portion of the flat cable held by the holder; and 
 an exterior forming step of forming a waterproof exterior portion covering, with an insulating resin, the holder, the round cable pulled out from the holder, and the flat cable pulled out from the holder. 
 
     
     
       7. The manufacturing method according to  claim 6 , wherein
 in the exterior forming step, exterior forming processing is performed while the flat cable is set in a state where the flat cable is bent to be guided in a direction different from a direction in which the flat cable is pulled out from the holder. 
 
     
     
       8. The manufacturing method according to  claim 6 , wherein
 the exterior forming step is an insert resin molding step in which a mold resin portion is molded by insert resin molding using, as inserts, the holder, the round cable pulled out from the holder, and the flat cable pulled out from the holder. 
 
     
     
       9. The manufacturing method according to  claim 6 , wherein
 the exterior forming step is a tube shrinking step in which the holder, the round cable pulled out from the holder, and the flat cable pulled out from the holder are arranged in a heat shrinkable tube with thermoplastic adhesive attached to an inner surface of the heat shrinkable tube, and a waterproof exterior portion is formed by changing a shape of the thermoplastic adhesive and the heat shrinkable tube by heating the heat shrinkable tube. 
 
     
     
       10. The manufacturing method according to  claim 6 , wherein
 the holder includes a round cable holder that holds the end portion of the round cable and a flat cable holder that holds the end portion of the flat cable, and 
 the cable setting step includes: 
 a cable holding step of holding the end portion of the round cable in the round cable holder and of holding the end portion of the flat cable in the flat cable holder; and 
 a holder combining step of combining the round cable holder and the flat cable holder in such a manner that the round cable from the round cable holder and the flat cable from the flat cable holder are pulled out in the same direction in the overlapped state.